Radish: plant running up to flower before it is ready to eat

What it is likely to be on radish

1. Bolting

   Candidate 1very common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Radish — cultivation
   • Royal Horticultural Society: Bolting

   Checked 2026-08-13

   A plant switching from leaf or root production to flowering and seed. It is the plant doing exactly what it evolved to do under stress, and it cannot be reversed — which makes bolting a problem of timing and cultivar choice rather than of treatment.

   Points towards it

   • · a radish is a six-week crop and warm weather runs it straight from seedling to flower without stopping to swell a root
   • · the whole sowing goes together, which is the shape of a response to weather and daylength
   • · long summer days and warmth in an open bed are the trigger
   • · warmth does it on its own, and dry soil brings it forward further

   Argues against it

   • · cool weather is what a radish wants, and a sowing that met a cold spell is more likely to be sitting still than running
   • · consistently wet soil keeps a radish in leaf and root rather than pushing it into flower

   Check this next

   Look at the date and at the spacing before blaming anything else. A radish bolts in midsummer because the days are long and warm, and it does it whether or not the soil is dry — a sowing made in April or September rarely does. Then pull one: a bolted radish has a thin woody root and a thickening stem, and if the row was sown thickly and never thinned, the plants have been competing since germination and will run sooner. Both of those are decisions made at sowing rather than problems that developed.

   What to do now

   Pull the row and sow again in the shoulders of the season rather than trying to rescue it — radishes are three weeks from sowing to eating and there is no reason to nurse a bolted one. Sow little and often from March to May and again from August to September, skipping the height of summer or moving to light shade, and thin to 2–3cm as soon as the seedlings are up. The leaves and the seed pods of a bolted radish are both edible, so the row is not wasted.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Radish — sowing and cultivation
   • Garden Organic — Garden Organic (Henry Doubleday Research Association): Succession sowing salad crops

   Checked 2026-08-13

2. Underwatering

   Candidate 2common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Rocket — cultivation
   • Royal Horticultural Society: Watering vegetables

   Checked 2026-08-13

   Easier to correct than overwatering and easily confused with it, because a plant short of water and a plant drowning both wilt. The distinguishing observation is not the plant at all — it is the compost, and it takes two seconds to check.

   Points towards it

   • · a check to a fast crop from dry soil is read by the plant as the end of its season, and it flowers rather than growing on
   • · the dry end of a row or the stretch under a fence bolts first while the rest carries on, which is what separates it from a whole-row response to weather
   • · the stem emerges from the centre while the outer leaves stay small and tough
   • · a bed under cover dries fastest of all and rocket grown in a tunnel bolts at half the size for exactly this reason

   Argues against it

   • · a plant that has never been short of water did not bolt from drought — this rules it out entirely.
   • · cool damp weather is when these two grow best and bolt least

   Check this next

   Measure the plant rather than reading the calendar. A radish or rocket that bolts from drought does it while it is half-sized — a rocket flowering at 10cm with small tough peppery leaves, a radish with a pencil-thin woody root — and it does it unevenly along the row, worst where the soil dries first. A plant that reached full size and then ran is responding to warmth and daylength instead. Push a finger to 5cm at the bolted end and at the sound end and compare; the difference is usually obvious.

   What to do now

   Water little and often rather than heavily and occasionally, which is the correct advice for shallow-rooted fast crops and the opposite of the advice for potatoes: keep the top 10cm consistently damp through the whole three to six weeks. Mulch lightly between the rows, sow into ground that has been watered rather than watering after sowing, and give a tunnel bed the same attention as an outdoor one — under cover it dries faster and gets forgotten. Pick rocket hard and often; a cut plant runs later than an uncut one.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Watering — how much and how often
   • Garden Organic — Garden Organic (Henry Doubleday Research Association): Salad crops under cover

   Checked 2026-08-13

Narrow it down

This page lists everything at once, which is the right shape for reading and the wrong shape for deciding. The interactive tool asks one question at a time, starting with whichever would separate these causes fastest, and stops as soon as further answers would not help.

Opens with the plant and the symptom already set. Nothing you answer is stored or sent anywhere — the answers live in the address bar and nowhere else.

What this does not cover

These are the causes GrowingHQ holds rules for on radish — not every cause there is. Where several problems look alike, the honest answer is often that they cannot be told apart by eye, and a page that named one would be guessing. If none of the above fits, the general plant running up to flower before it is ready to eat page lists causes across all plants, and the Radish profile lists the problems it is prone to.